The jury trial of an 82-year-old retired Harvard professor charged with vehicular homicide of a Newton Country Day teacher is scheduled to begin Sept. 28 in Newton District Court, according to court documents.

Chloe Gotsis, staff writer

The jury trial of an 82-year-old retired Harvard professor charged with vehicular homicide of a Newton Country Day teacher is scheduled to begin Sept. 28 in Newton District Court, according to court documents.

Detlev Vagts, of Cambridge, told police that he and his wife were running late for an appointment near Hammond Street on July 8, 2010 when his blue 2010 Subaru hit and allegedly killed 54-year-old Marcia Kearney, 54, of Northampton, on her green Vespa, according to police reports. Vagts was arraigned on Dec. 20 on a charge of motor vehicle homicide.

He is next scheduled to be in court on Aug. 28 for a status review of his case prior to the trial.

Prosecutors expect Vagts’ trial to last two days. Court documents say that the jury is expected to hear testimony from four witnesses on the prosecution side and two for the defense.

According to police reports Kearney died from a traumatic cardiac arrest with a brain hemorrhage.

Vagts told police that he was running late for a dentist appointment and got lost after he was detoured from Fanueil Street in Brighton and ended up on Waverly Avenue in Newton. Vagts told police that as he turned onto Ward Street he saw a person in front of him on a bike attempting to turn left onto Grant Avenue, according to police reports.

He told police he hit the Vespa and swerved left after seeing the woman’s helmet in front of his car. Police reports say that Vagts’ car came to a stop after it hit the curb, but Vagts continued to drive down the street at least 448 feet before turning around and returning to the crash site.

A witness at the scene told police that Vagts didn’t return to the scene for at least two minutes after hitting the Vespa.

Other witnesses told police they heard the Vespa being dragged underneath the Subaru “for a long time.” According to police reports, medical examiners found Kearney’s body 82 feet from the crash scene when they arrived.

Vagts told the TAB in July that he doesn’t think the accident was his fault.

The maximum sentence for a vehicular homicide charge is 2 ½ years in jail or a House of Correction.

Staff writer Chloe Gotsis can be reached at 781-433-8333 or at cgotsis@wickedlocal.com